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The QCTP is a model 200 from Arc Euro Trade (www.arceurotrade.co.uk).
It's very much overkill for a ML10, but my plan was so I can swap tools with my bigger lathe which already has a model 200 and a good few holders. However I'm now thinking it'll be better having seperate tools, as the faff involved with changing tool heights between the lathes kinda kills the benefit of using a QCTP, plus the QC handle means I can't close the cover.
Argh!!!
Thought I'd do the right thing, and connect up all the sheilding wires to ground, but it meant the spindle sensor started giving some very erratic readings (3 million rpm is just slightly high...)
So cut the sheilding wire, and things went back to being stable.
I'm just going to leave the ground wires of for now, as everything appears to work how it should with them off. I think the real issue is that with the current control box layout, the ground wires are having to run past the transformer, bridge rectifiers, and capacitors, and they're picking up interference from them. I could redo the control box, but I'm wanting to make parts, so I'll leave that for a future upgrade, as I'm not entirely happy with the current break out board (even though it's repaired, I'm not 100% convinced by it's reliability).
Just need to get a couple airline connectors now, and get the control cabinet screwed shut, so I can get the lathe turned around and the workshop rearranged for the other new toy.
With little else to do tonight, I thought I'd get the new backplate on, and machine it up for the ER collet chuck I've had lying around for a while.
Expecting the 3jaw to be seized on, I was surprised that it came of with gentle use of some mole grips (because Conect removed the original pulley block, there's no spanner flats on the headstock) and a lever, it slackened with no need to resort to expletives.
Spun the new backplate on, nipped it up, then hit the first problem.
The carriage wouldn't move near enough to the headstock for the tool to reach the backplate. After much umming and r'ing, going through the tool collection, thinking it was the ball screw cover at the headstock end bottoming out, which would involve a lot of dismantling to remove, it finally dawned on me the problem was the ballscrew cover at the tailstock end, so with one screw removed, I had the required travel.
So onto getting some G-code to face the backplate. Loaded the wizards in Mach, and first attempt cutting air done the wrong thing, so while putting some more figures into the wizard, I'm aware of a crackling sound, the lights briefly dim, then a pop, followed by the dreaded smell.
Turns out the toiroid has melted itself, but there's no obvious reason why.
The fibre washer on the mounting bolt looks to be where it should of been, so that's not caused it, but it has been heating for a while going by the melted tape and how hot it still was by the time I pulled the lathe out and unscrewed the back cover.
There is a arcing mark on the base, so I wonder if a bit swarf has worked it's way in somewhere causing the problems :confused:
Anyway, here's a couple photos of the culprit
Attachment 4593Attachment 4594
I've already had a search for a direct replacement, but dual voltage toiroids seem to be pretty rare, as this had a 12V and a 24V secondary.
Think this may be a suitable time to up the voltage aswell, as those geckos are good for 50V, and the basic motor calcs say they should handle the voltage....:naughty:
That is just not nice. Good luck on getting either a new one (they be hard to find as you noted) or one that will meet the required need.
Michael
Hmm, that must be extremely annoying. I've got two transformers on my machine - 500VA powering X motors and Z, 325VA on Y and 4th axis if in use. I only did it as I had a spare and thought it would be good to seperate the supply for X and Y so that if they both draw a high current at the same time (e.g. G0 X0Y , G0 X500 Y500) the voltage doesn't drop too much. Will also help if one goes bang, but they never even get warm so can't see that hapenning. Really odd that yours did since your drivers have overcurrent protection. What did you fuse did you use?
It'd be interesting to try rewinding/repairing the existing transformer. Depending on how many turns that arcing has destroyed you might be able to remove those turns and connect up the loose ends. Then switch it on with no load from a distance ... if it seems fine after a couple of minutes try measuring the voltage.
I'm not sure what happened, as nothing was moving at the time.
I was trying to figure out how to get the Mach wizard to do an outside to inside facing cut, when I heard something starting to crackle.
The only thing I can think of, was I fixed the coolant earlier, and at one point I rattled the back of the casing quite hard when trying to get the locline back together, so I wonder if I dislodged something, but the only obvious damage is the toiroid. Fuses are 6.3A anti-surge.
That is much too high to protect the transformer. For that 160VA transformer 2A slow blow would have been more appropriate. Probably 3A slow blow for the new one, maybe less...Quote:
Originally Posted by m_c
The fuse powers the tx and the spindle drive, as that was the original setup that I never changed.
Think i'll add an extra fuse now though!
New TX and assorted bits now ordered.
Ended up getting the stuff from RS, as they were the cheapest ones who had everything in stock.
Bits should hopefully be here on thursday, but I probably won't get them in place until sunday/monday.
The lathe is finally back up and running.
Machined the new backplate for a ER32 collet chuck this week, which took a few attempts to find a suitable feed rate and depth of cut due to the lack of power at low RPM, but got it done eventually.
I'm already considering a PoKey and MPG, as having to move between the lathe and the computer when setting up/jogging/starting/stopping is a pain.